A Study of Power Supply Variation as a Source of Random Noise

In this paper, we consider the construction of True Random Numbers Generators (TRNGs) using variations in power supplies. We demonstrate that power supply line outputs do not have a constant voltage and the variations in voltage follow a normal distribution. These variations can be used to create truly random bits that demonstrates a high entropy rate based on the results obtained from the NIST Statistical Test Suite. In order to quantify the impact of variations on the input signal of a circuit, we analyze the impact of such variations using Monte-Carlo simulations as well as an actual implementation. Results were obtained for evaluating the accuracy and randomness of the data gathered from our proposed circuit. A detailed analysis of the effect of variations of different power supplies is also presented with observations on their usefulness as a TRNG. The key advantage of our power supply variation based TRNG is its simplicity of implementation.